Continuous variation of genic dosage in<i>Phycomyces</i>

Medina, J. R.

doi:10.1017/s0016672300017626

Cited by 8 publications

(3 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The wild mating type (-) of P. b/akes/eeanus, IGE1101 (--NRRL 1555), was used carA5 (--) From NRRL1555 (Meissner and Delbr~ck, 1968) C5 carBlOgeo-10 (-) From NRRL1555 (Isolated by M. Heisenberg) S 102 nicA 101 (-) From NRRL1555 (Medina, 1977 (--) From S 102 in this work to estimate chlorate effects. Chlorate resistant mutants were induced from S 102, a nicotinic acid-requiring auxotrophic mutant (genotype nic) derived from NRRL 1 555.…”

Section: Methodsmentioning

confidence: 99%

Isolation and characterization of chlorate resistant mutants from nitrate-nonutilizing fungus Phycomyces blakesleeanus

2000

View full text Add to dashboard Cite

Chlorate resistant mutants, which were first isolated in the zygomycetous fungus Phycomyces blakesleeanus, were found to be resistant up to a concentration of at least 300 mM of potassium chlorate. The dose-response relationship showed that although the mutants could be divided into two groups based on chlorate resistance in the mycelial elongation assay on the solid minimal medium, this was not observed in the assay using liquid culture. Genetic analysis of heterokaryons revealed the mutant alleles to be dominant. Enzymatic activities of three nitrate reductases and chlorate reductase were deficient in both the parent strain and the mutants. Intracellular incorporation of chlorate ion varied from strain to strain; however, the variation could not explain the mechanism of chlorate resistance. One unexpected characteristic of the mutants was that the intracellular sulfate ion concentration was 3.5 to 5.5 times higher than in the parent strain. We designated this mutant genotype crw, chlorate resistant mutant from nitrate-nonutilizing wild type.

show abstract

Section: Methodsmentioning

confidence: 99%

Isolation and characterization of chlorate resistant mutants from nitrate-nonutilizing fungus Phycomyces blakesleeanus

2000

View full text Add to dashboard Cite

show abstract

“…The strains of P . blakesleeanus used in this work were the wild-type NRRL 1555 and the mutant S102, an auxotroph for nicotinic acid (Medina, 1977); the mutant strains that we obtained are described in Results. Culture media used (Sutter, 1975) were SIV, a glucose/asparagine minimal medium, and SIVY, which is a minimal medium supplemented with 1 mg yeast extract ml-l. For colony growth, SIV and SIVY were acidified to pH 3.3 (SIVA and SIVYA, respectively).…”

Section: Methodsmentioning

confidence: 99%

“…Since the behaviour of MU102 partially resembled that of some well-characterized cytoplasmic mutants of other filamentous fungi, a 'heterokaryon test' (Jinks, 1958) was done using MU102 and S102; the latter strain harbours a nuclear recessive mutation leading to nicotinic acid auxotrophy (Medina, 1977). After screening 200 colonies from several heterokaryons, three Nic-, copper-resistant colonies were isolated, all of them showing, in addition, the other phenotypic traits of MU102.…”

Section: He Tero Karyon Testmentioning

confidence: 99%

A cytoplasmically inherited mutation in the fungus phycomyces blakesleeanus

Arnau¹,

Murillo²,

Torres‐Martínez³

1990

Journal of General Microbiology

View full text Add to dashboard Cite

Fourteen mutants of the fungus Phycomyces blakesleeanus, showing high levels of resistance to copper, were isolated. In all the mutants, copper resistance behaved as a very variable and unstable trait. In the mutant strain MU102, the mutation was demonstrated to be cytoplasmically inherited. In addition, this mutant strain differed from the wild-type in growth, respiration rate, and shape and viability of spores.

show abstract

Chitin synthetase mutants of Phycomyces blakesleeanus

1993

View full text Add to dashboard Cite

Mutants resistant to nikkomycin, an inhibitor of chitin biosynthesis, were isolated after exposure of wild-type spores of the fungus Phycomyces blakesleeanus to N-methyl-N'-nitro-N-nitrosoguanidine. Genetic analysis revealed that nikkomycin resistance was due to mutations in a single gene, chsA. Mutants and wild type grew equally well in the absence of nikkomycin. In contrast to the wild type, whose spore germination and mycelial growth were inhibited by 5 microM nikkomycin, chsA mutants grew reasonably well in the presence of 50 microM nikkomycin. Chitin synthesis in vivo was much less affected by the drug in the mutants than in the wild type. Resistance was not due to impaired uptake or detoxification of the drug. Analysis of the kinetics of chitin synthesis in vitro showed that the mutants had a decreased Ka for the allosteric activator, N-acetylglucosamine, and gross alterations in nikkomycin inhibition kinetics. These results indicate that chsA is the structural gene for chitin synthetase, or at least for the polypeptide that bears the catalytic and allosteric sites.

show abstract

Continuous variation of genic dosage inPhycomyces

Cited by 8 publications

References 12 publications

Isolation and characterization of chlorate resistant mutants from nitrate-nonutilizing fungus Phycomyces blakesleeanus

Isolation and characterization of chlorate resistant mutants from nitrate-nonutilizing fungus Phycomyces blakesleeanus

A cytoplasmically inherited mutation in the fungus phycomyces blakesleeanus

Chitin synthetase mutants of Phycomyces blakesleeanus

Contact Info

Product

Resources

About